300-440 Exam Dumps : Designing and Implementing Cloud Connectivity (ENCC)

Step 1 = Create a Customer Gateway (CGW) in AWS. Step 2 = Create a Virtual Private Gateway (VGW) in AWS. Step 3 = Create a site-to-site VPN connection in AWS. Step 4 = Configure the IOS XE router with the required IPsec VPN parameters and routing settings. Step 5 = Verify and test the VPN connection.

The process of configuring a site-to-site VPN connection between an on-premises Cisco IOS XE router and Amazon Web Services (AWS) involves several steps12.

• Create a Customer Gateway (CGW) in AWS: This is the first step where you define the public IP address of your on-premises Cisco IOS XE router in AWS1.
• Create a Virtual Private Gateway (VGW) in AWS: This involves creating a VGW and attaching it to the VPC in AWS1.
• Create a site-to-site VPN connection in AWS: After setting up the CGW and VGW, you then create a site-to-site VPN connection in AWS. This involves specifying the CGW, VGW, and the static IP prefixes for your on-premises network1.
• Configure the IOS XE router with the required IPsec VPN parameters and routing settings: After the AWS side is set up, you configure the on-premises Cisco IOS XE router with the required IPsec VPN parameters and routing settings2.
• Verify and test the VPN connection: Finally, you verify and test the VPN connection to ensure that it is working correctly12.

References :=

• Configure IOS-XE Site-to-Site VPN Connection to Amazon Web Services - Cisco Community
• SD-WAN Configuration Example: Site-to-site (LAN to LAN) IPSec between vEdge and Cisco IOS - Cisco Community

 BFD (Bidirectional Forwarding Detection) is a protocol that detects failures in the overlay tunnel between Cisco SD-WAN devices. BFD packets are sent and received periodically by each device to check the liveliness and quality of the connection. If a device does not receive a BFD packet from its peer within a specified timeout interval, itconsiders the peer to be unreachable and reports a BFD down event. This event triggers a control connection state change and a possible route change in the SD-WAN fabric.

In this scenario, the engineer discovers that BFD is flapping on vEdge1, which means that the BFD session between vEdge1 and the remote Edge device is going up and down repeatedly. This indicates a connectivity issue between the two devices, such as network congestion, packet loss, or misconfiguration. The most likely cause of the problem is that the remote Edge device failed to respond BFD keepalives within the timeout interval, which resulted in a BFD timeout event on vEdge1. This event caused vEdge1 to mark the remote Edge device as down and notify the control plane. The control plane then tried to establish a new BFD session with the remote Edge device, which may have succeeded or failed depending on the network condition. This cycle of BFD session creation and deletion caused the BFD flapping on vEdge1.

The other options are less likely to be the cause of the problem. Option A is incorrect because if the remote Edge device BFD was down, vEdge1 would not receive any BFD packets from it and would not flap. Option C is incorrect because if the remote Edge device had a duplicate IP address, vEdge1 would not be able to establish a BFD session with it in the first place. Option D is incorrect because the control plane does not delete the BFD session unless there is a configuration change or a port-hop event on the device. References: Bidirectional Forwarding Detection Flap-Reason Definitions on Cisco vEdge Routers, Cisco Catalyst SD-WAN BFD, Cisco SD WAN: BFD (Bidirectional Forwarding Detection)

The role of service providers to establish private connectivity between on-premises networks and Google Cloud resources is to facilitate direct, dedicated network connections through Google Cloud Interconnect. Google Cloud Interconnect is a service that allows customers to connect their on-premises networks to Google Cloud through a service provider partner. This provides low latency, high bandwidth, and secure connectivity to Google Cloud services, such as Google Compute Engine, Google Cloud Storage, and Google BigQuery. Google Cloud Interconnect also supports hybrid cloud scenarios, such as extending on-premises networks to Google Cloud regions, or connecting multiple Google Cloud regions together. Google Cloud Interconnect offers two types of connections: Dedicated Interconnect and Partner Interconnect. Dedicated Interconnect provides physical connections between the customer’s network and Google’s network at a Google Cloud Interconnect location. Partner Interconnect provides virtual connections between the customer’s network and Google’s network through a supported service provider partner. Both types of connections use VLAN attachments to establish private connectivity to Google Cloud Virtual Private Cloud (VPC) networks. References:

• Designing and Implementing Cloud Connectivity (ENCC) v1.0
• [Google Cloud Interconnect Overview]
• [Google Cloud Interconnect Documentation]